Mark Lawrence Schrad remembers vividly his first day in Russia in the 1990s.
"I got off the plane, just coming out of the metro station ... this guy was walking past the metro with this massive gushing head wound and blood dripping all over. [He was] dashing his hand with vodka, and then splashing the vodka onto his wound," he says.
And this wasn't a surprising scene for anyone around him.
Now Schrad has written a book called "Vodka Politics: Alcohol, Autocracy and the Secret of the Russian State."
He says vodka has deep roots in Russia. But he says a few hundred years ago, it was not the dominant beverage.
"Just like most of Europe, there was a deep tradition of brewing beers, ales and porters," he says.
Then, in the 1500s and 1600s, came the introduction of distilling technologies.
Schrad says the Russian government had a monopoly on the tavern trade. And the most profitable drink was vodka.
"Slowly, over time, ... [taverns] didn't want to provide beers and wine any more because it wasn't profitable and that left people with the only option ... vodka," he explains.
Today, there is what Schrad calls "vodka diplomacy," practiced at large banquets that the Russians throw every time there is a major political event.
"They would have round after round of toasts, in some cases 20 or 30 rounds, before the meal begins. And that, often time, is enough to get even the most alcohol-tolerant person a little tipsy," he adds.
An example of this was when Winston Churchill went to visit Stalin in the 1940s, and in the 1990s, when foreign dignitaries went to visit Boris Yeltsin.
Schrad says offering vodka to guests can be used "to keep people off balance and maybe [give away] some secrets that they might otherwise be harboring."